#define  _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>


typedef int QDataType;
typedef struct QueueNode
{
	struct QueueNode* next;
	QDataType data;
}QNode;

typedef struct
{
	QNode* head;
	QNode* tail;
	int size;
}Que;

void QueueInit(Que* pq);
void QueueDestroy(Que* pq);
void QueuePush(Que* pq, QDataType x);
void QueuePop(Que* pq);
QDataType QueueFront(Que* pq);
QDataType QueueTail(Que* pq);
bool QueueEmpty(Que* pq);
int QueueSize(Que* pq);
void QueueInit(Que* pq)
{
	assert(pq);
	pq->head = pq->tail = NULL;
	pq->size = 0;
}
void QueueDestroy(Que* pq)
{
	QNode* cur = pq->head;
	while (cur)
	{
		QNode* next = cur->next;
		free(cur);
		cur = next;
	}
	pq->head = pq->tail = NULL;
	pq->size = 0;
}
void QueuePush(Que* pq, QDataType x)
{
	assert(pq);
	QNode* newnode = (QNode*)malloc(sizeof(QNode));
	if (newnode == NULL)
	{
		perror("malloc fail\n");
		exit(-1);
	}
	newnode->next = NULL;
	newnode->data = x;
	if (pq->tail == NULL)
	{
		pq->head = pq->tail = newnode;
	}
	else
	{
		pq->tail->next = newnode;
		pq->tail = newnode;
	}
	pq->size++;
}
void QueuePop(Que* pq)
{
	assert(pq);
	assert(!QueueEmpty(pq));
	if (pq->head->next == NULL)
	{
		free(pq->head);
		pq->head = pq->tail = NULL;
	}
	else
	{
		QNode* next = pq->head->next;
		free(pq->head);
		pq->head = next;
	}
	pq->size--;
}
QDataType QueueFront(Que* pq)
{
	assert(pq);
	assert(!QueueEmpty(pq));
	return pq->head->data;
}
QDataType QueueTail(Que* pq)
{
	assert(pq);
	assert(!QueueEmpty(pq));
	return pq->tail->data;
}
bool QueueEmpty(Que* pq)
{
	assert(pq);
	return pq->head == NULL;
}
int QueueSize(Que* pq)
{
	assert(pq);
	return pq->size;
}

typedef struct
{
	Que q1;
	Que q2;
} MyStack;


MyStack* myStackCreate()
{
	MyStack* obj = (MyStack*)malloc(sizeof(MyStack));
	QueueInit(&obj->q1);
	QueueInit(&obj->q2);
	return obj;
}

void myStackPush(MyStack* obj, int x)
{
	if (!QueueEmpty(&obj->q1))
		QueuePush(&obj->q1, x);
	else
		QueuePush(&obj->q2, x);
}

int myStackPop(MyStack* obj)
{
	Que* empty = &obj->q1;
	Que* nonempty = &obj->q2;
	if (!QueueEmpty(&obj->q1))
	{
		empty = &obj->q2;
		nonempty = &obj->q1;
	}
	while (QueueSize(nonempty) > 1)
	{
		QueuePush(empty, QueueFront(nonempty));
		QueuePop(nonempty);
	}
	int top = QueueFront(nonempty);
	QueuePop(nonempty);
	return top;
}

int myStackTop(MyStack* obj)
{
	if (!QueueEmpty(&obj->q1))
		return QueueTail(&obj->q1);
	else
		return QueueTail(&obj->q2);
}

bool myStackEmpty(MyStack* obj)
{
	return QueueEmpty(&obj->q1) && QueueEmpty(&obj->q2);
}

void myStackFree(MyStack* obj)
{
	QueueDestroy(&obj->q1);
	QueueDestroy(&obj->q2);
	free(obj);
}
